Tenets of quantum mechanics and special relativity, among other theoretical ideas, lead inexorably to string theory.

Physicists may have uncovered a surprising new clue that string theory—the idea that the universe is built from unimaginably tiny vibrating strings—could be more than just a mathematical fantasy.

Cosmic strings are hypothesised one-dimensional topological defects formed during symmetry-breaking phase transitions in the early Universe. As these strings evolve, they intersect and form loops ...